Early
efforts in the field date to the 1940s, when scientists developed
pneumatic “artificial muscles” to be used in traditional robots.

Progress has inched along since then, producing small-scale projects
like scooting soft-bodied caterpillars and pneumatic quadrupeds.

But the advent of 3D printing has greatly accelerated the chase.

Dr.
Majidi said the technology had been “a bit of a game-changer,” enabling
just about any research team — or garage tinkerer — to make new molds
to create stretchy prototypes, a process that just a few years ago was
slow and costly.

And here in Italy,
Dr. Giorgio-Serchi and his colleagues recently acquired a 3D printer
that allows them to design, experiment and revise quickly.

They
aim to replicate the key features of an octopus: eight arms to provide
an almost infinite range of motion; the ability to squeeze through any
opening larger than its chitinous beak; and an unusual nervous system in
which the arms are semiautonomous and the central brain is thought to
do little more than issue general commands (“Arms, let’s go catch that
crab!”).

To
make quicker headway, some of the PoseiDrone’s components, such as the
electronics, remain hard for now.

The exterior will be silicone — a
material whose density, like that of an octopus, is similar to water’s.

In contrast to a hard-bodied underwater bot, which would
need to hover at a safe distance from such equipment, the PoseiDrone
should be able to attach itself directly without damaging the equipment
or itself, Dr. Giorgio-Serchi said.

Sending robots down to perform
dangerous tasks could also help keep human divers safer.

The drone can already crawl, swim and even carry small tools.

But it is not yet ready to repair a turbine.

PoseiDrone: a soft-bodied ROV

And
although the researchers are applying for patents, it is still a crude
specimen, a robotic Frankenstein’s monster bridging the eras of hard and
squishy — currently only 80 percent soft materials.

“It’s
still very much a work in progress,” Dr. Majidi said. And Mark R.
Cutkosky, a professor at the Stanford School of Engineering, said: “How
do we build stretchy conductors? That’s still a very open question.”

“It
sounds pretty prosaic,” he added, “yet one of the biggest challenges is
just wiring.

This was true 20 years ago, and it’s still true.”

The
PoseiDrone’s movements still rely on external control of conventional
motors and actuators.

Nevertheless,
the octopus robot is more sophisticated than a standard robot covered
in rubber, Dr. Giorgio-Serchi said.

Its abundance of soft, elastic
materials enables it to do things most other robots cannot — much as
stiff-jointed humans cannot do what an octopus can, despite our soft
skin and muscles.

“Without the soft part,” Dr. Giorgio-Serchi said, “it would just be a pile of motors and cables.”

Also
like real cephalopods, the PoseiDrone, whose body is about the length
of an adult human hand, could be just about any scale — from fractions
of an inch to dozens of feet across.

A larger version is in the works.

And perhaps not reassuring to those who fear a robot uprising, the
bigger it is, “the easier it is to make it stronger — and fast,” Dr.
Giorgio-Serchi said.

Virtually
any conceivable form is now just a click away, so why do researchers
focus on animal models? Dr. Cutkosky, who has built a climbing robot with gecko-inspired grippers, says we inevitably look to the natural world for inspiration.

And
caution.

Comparing the octopus robot to its real-life counterpart, he
said, “It’s probably a good thing they’re confined to water.”